Heater blowing cold air or semi warm but never hot uncomfortably cold

Unless you possess the proper automobile troubleshooting skills - it is going to be difficult for us here online to express what needs to be done here. A couple of diy suggestions is check coolant level while engine is COLD .. Antifreeze smell inside cabin is indicative of a heater core leak - passenger side carpet may be wet - under floor mat. Untimely this is going to require *hands-on* assistance from qualified personnel.